package com.itheima03;

import java.util.ArrayList;
import java.util.TreeSet;

public class DaoSshou {
    public static void main(String[] args) {
        ArrayList<String> s1 = new ArrayList<>();
        s1.add("11");
        s1.add("11");
        s1.add("22");
        s1.add("33");
        s1.add("44");
        System.out.println(s1);
        TreeSet<String> s2 = new TreeSet<>();
        //互相倒手去除重复的数据
        s2.addAll(s1);
        System.out.println(s2);
        s1.clear();
        s1.addAll(s2);
        System.out.println(s1);
    }
}
